Brown and McGreal take temporary charge.Colchester United Chairman Robbie Cowling has installed Wayne Brown as Caretaker Manager.
The former U's defender will be assisted by John McGreal while decisions are made on a permanent appointment.
Robbie said of the interim arrangement:-
"Wayne Brown and John McGreal have been asked to take charge of first team matters at Colchester United on a caretaker basis whilst with the help of my fellow directors, I determine the next full-time management team.
For last weekend's match at Burton, the U's were led by Richard Hall and Robbie added: "Richard very much remains a part of the club and the equation going forward."
"I hope everyone involved with Colchester United can get behind Wayne and John and give them their full support."
"I am pleased to say that they have both accepted those roles and I would like to express my thanks to them both for helping the club out.